Figure 4

Increased infiltration of neutrophils and macrophages in the arthritic SKG mice versus the non-arthritic Balb/c mice. (a to j) Naphthol AS-D chloroacetate esterase staining of the lungs staining for neutrophils. (a) Balb/c; (b) Balb/c + Zymosan; (c) Balb/c + Zymosan + TUBO; (d) Balb/c + Zymosan + 4T1; (e) SKG (moderate infiltration of neutrophils); (f) SKG + TUBO(moderate infiltration); (g) SKG + 4T1(severe infiltration of neutrophils); (h) SKG + Zymosan(moderate infiltration); (i) SKG + Zymosan + TUBO (moderate infiltration); (j) SKG + Zymosan +4 T1(severe infiltration of neutrophils). No infiltration of neutrophils observed in any other experimental groups. (k to t) F4/80 staining of the lungs showing macrophages. (k) Balb/c; (l) Balb/c + Zymosan; (m) Balb/c + Zymosan + TUBO; (n) Balb/c + Zymosan + 4T1; (o) SKG; (p) SKG + TUBO; (q) SKG +4T1 (increased macrophages); (r) SKG + Zymosan (few macrophages); (s) SKG + Zymosan + TUBO (few macrophages); (t) SKG + Zymosan + 4T1 (increased infiltration of macrophages). No infiltrating macrophages observed in any other experimental groups. (u) BAL fluid from arthritic lungs caused significant increase in invasiveness of the 4T1 cells as compared with the BAL from non-arthritic lungs. All images taken at 200 × magnification. All slides were examined by the histology personnel and Dr Gruber at the Carolinas Medical Center confirming neutrophil infiltration.